1. Technical Field
The present invention relates to a battery management system. More particularly, the present invention relates to a battery management system used in a vehicle using electrical energy, and a driving method thereof.
2. Related Art
A vehicle using an internal combustion engine, and using gasoline or heavy oil as a main fuel, has a serious influence on the generation of environmental pollution, such as air pollution. In recent years, much effort has been made to develop an electric vehicle or a hybrid vehicle so as to reduce the generation of environmental pollution.
The electric vehicle is a vehicle which uses a battery engine which operates by means of electrical energy output from a battery. The electric vehicle uses a battery in which a plurality of rechargeable secondary cells is provided as one pack and as its main power source. Thus, the electric vehicle has advantages in that there is no discharge gas, and the noise is very small.
The hybrid vehicle is an intermediary vehicle between the vehicle using an internal combustion engine and the electric vehicle. The hybrid vehicle uses two or more power sources, for example, an internal combustion engine and a battery engine. At present, a hybrid vehicle which uses an internal combustion engine and a fuel cell for continuously supplying hydrogen and oxygen while inducing a chemical reaction to directly obtain electrical energy, or which uses a battery and a fuel cell, is being developed.
In the vehicle using the battery engine, secondary battery cells are increasing in number so as to improve the power source, and a plurality of connected cells have a direct influence on the performance of the vehicle. Thus, there is a requirement for a battery management system (BMS) in which each battery cell should not only be excellent in performance, but also a BMS in which the voltage of each battery cell and the voltage and current of the entire battery are measured, and charge and discharge of each battery cell is effectively managed.
In particular, the internal resistance of the battery has a direct relation to an output reduction and a fatigue state of the battery, and it is used as a reference for determining the lifespan and the state of health (SOH) of the battery. Thus, there is a requirement to more accurately measure the internal resistance of the battery so as to determine the lifespan and the SOH of the battery having the direct influence on the performance of the vehicle.
The information disclosed above is only for enhancement of an understanding of the invention, and thus it does not necessarily form the prior art already known to a person of ordinary skill in the art.